1. Field of the Invention
The present invention relates to a network management system and more particularly to a method of and an apparatus for calculating transit traffic in individual routers.
2. Description of the Background Art
One of conventional schemes for collecting traffic statistics on a telecommunications network uses an RMON2 (Remote network MONitoring 2) feature particular to an SNMP (Simple Network Management Protocol). The RMON2 feature includes an MIB (Management Information Base) referred to as n1Matrix. The n1Matrix MIB indicates statistics on the transfer of L3 (Layer 3) packets switched via any desired network segment. More specifically, the n1Matix MIB collects information on the headers of L3 packets and stores statistics between end-to-end terminals in the form of a matrix of destination L3 addresses and source L3 addresses. The statistics include the total number of packets transferred and the total number of octets transferred.
The RMON2 feature is installed in a router, which transfers L3 packets, in the form of software or LSI (Large-Scale Integration) circuit for filtering packets, or in the form of monitoring device exclusively directed to packet filtering.
An NMS (Network Management System) that manages a telecommunications network uses the SNMP to collect the statistics from routers or monitoring devices having the RMON2 feature.
The n1Matrix MIB particular to the RMON2 feature is representative of statistics on the traffic of a desired network segment. The n1Matix MIB is therefore preferably applicable to grasping the concentration of traffic on a certain server or the congestion of traffic in a network segment. However, such statistics do not allow traffic in an individual or specific router to be grasped alone.